The use of commercial feedlots for the fattening of cattle was introduced only a few years ago, but because of the relative profitability of this approach, it has rapidly grown in popularity and now completely dominates the cattle-fattening industry. Large numbers of cattle running to the thousands and tens of thousands are brought to these lots where they are concentrated in relatively close quarters.
The problems associated with these feedlots have grown at the same rate, however, and now represent a major national concern. The odors produced by the lots have created serious problems, especially when the feedlots have been located near population centers. Waste materials carried into the soil by rainwater runoff threaten pollution of ground water and pose a serious health hazard to the surrounding communities. The accumulation of manure at the feelots is also a hazard to the health of the cattle themselves because of the contamination of the air and because it attracts flies and other insects.